An airway study of different maxillary and mandibular sagittal positions

The aim of this study was to evaluate the oropharyngeal (OP) and nasal passage (NP) volumes along with various airway variables of patients with normal nasorespiratory functions having different dentofacial skeletal patterns and to evaluate the correlations between different variables and the airway. One hundred and one patients (57 males and 44 females, aged 14-18 years) having pre-treatment cone beam computed tomography images and complete medical records were selected. The patients were divided into five groups as Class I (CI, 81 ≥ SNA ≥ 77; 80 ≥ SNB ≥ 76; 3 ≥ ANB ≥ 1), Class II maxillary protrusion (CIIMaxP, SNA > 81; 80 ≥ SNB ≥ 76; ANB > 3), Class II mandibular retrusion (CIIMandR, 81 ≥ SNA ≥ 77; SNB < 76; ANB > 3), Class III maxillary retrusion (CIIIMaxR, SNA < 77; 80 ≥ SNB ≥ 76; ANB < 1), and Class III mandibular protrusion (CIIIMandP, 81 ≥ SNA ≥ 77; SNB > 80; ANB < 1). Posterior airway space, area of the most constricted region at the base of the tongue (minAx), and OP volume were significantly higher for the CIIIMandP group, whereas CIIMandR subjects had the lowest values. The only significant difference for the NP volume was between CI and CIIMandR groups where a smaller volume for the CIIMandR group was observed. The minAx was the variable that presented the best correlation with the OP airway volume. It seems that a detailed analysis of airway may prove to be a valuable diagnostic addition in orthodontics.